sequenceLastValue(p_seqname)
Utility function used in sl_seqlastvalue view to compactly get the
last value from the requested sequence.
declare
p_seqname alias for $1;
v_seq_row record;
begin
for v_seq_row in execute 'select last_value from ' || slon_quote_input(p_seqname)
loop
return v_seq_row.last_value;
end loop;
-- not reached
end;